Process of manufacturing iron-coke



TOTAL. com, CHARGE Dec. 29, 1959 Y E. E. DONATH PROCESS OF MANUFACTURING IRON-COKE Filed Aug. 24, 1954 MIXING IJZON OX I DE FINES BLBNDI NG COKING INVENTOR. EBA/5ST 1S. Domqr/v' United States Office 2,919,231 PROCESS OF MANUFACTURING IRON-COKE Ernest E. Donath, Pittsburgh, Pa., assiguor to Koppers Company, Inc., a corporation of Delaware Application August 24, 1954, Serial No.'451,976

6 Claims. 01. 202-34 The present invention relates to a process of manufacturing coke and more particularly to a process of manufacturing iron-coke.

For a number of years, the coking industry has been active in the production of metallurgical coke by mixing coal destined for coking chambers with finely-divided, iron oxide-bearing materials. The mixing of the iron oxide fines with the coal to be coked has been accomplished all at one time in substantially the same manner that low-volatile and high-volatile coals are mixed in coke oven plants prior to coking. This manner of mixing, however, has left much to be desired because of the differences in particle sizes in the coals and the iron oxidefines, the differences in moisture content of these two materials and consequent difference in the ability of the two materials to flow at uniform rates from the conveying equipment. Because of the lack of intimate mixing of the coal and the iron oxide fines, the iron oxide is not uniformly distributed throughout the mass of coal. This results in a lower coke strength when the mixture of these two materials is carbonized. In addition, this situation results in some of the iron oxide fines and/or coal dust being carried off with the gaseous materials formed during the coking process, these dusts thereby depositing in and plugging the gas off-take pipes.

The present invention avoids these aforementioned disadvantages by providing a process of producing ironcoke whereby intimate mixture of the iron oxide and coal is obtained, resulting in a stronger coke product and one in which a larger amount of the iron oxide is reduced to the metallic state.

Another feature of the present invention is to provide a process which permits easy handling of the materials used in the production of iron-coke and which avoids undesirable dust formation. Still another feature of the present invention is to provide a process which permits intimate mixing of the iron oxide and coal prior to carbonization, thus minimizing undesirable reoxidation of the metallic iron derived from the reduction of the iron oxide during the coking process.

Various other features of the present invention will become evident from the herein disclosure.

More particularly, the present invention provides a process of manufacturing iron-coke comprising the steps of intimately mixing iron oxide fines with a small or minor portion of a total coal charge with which the fines are to be mixed, blending this iron oxide-coal mixture with the remaining or major portion of the total coal charge and coking the the blended mixture.

It is to be understood that various changes and modifications can be made by one skilled in the art in the several steps of the hereinafter disclosed process without departing from the scope or spirit of this invention.

The drawing discloses the inventive process in flow sheet form.

In carrying out the present invention, a portion of a total coal charge to be coked is mixed with iron oxide fines which can be one of a number of iron ores such as i 2,919,231 Patented Dec. 29, 1959- 2 the steps of intimately mixing iron oxide fines with a taconite concentrates, magnetite or hematite ores or concentrates from various sources or which can be blast furnace flue dust. The mixing can be accomplished in various types of known comminuting mechanical mixing devices. For example, a ball mill type mixer can be used. In an advantageous embodiment of the invention, the coal to be mixed with the iron oxide fines can be of fine size, preferably between 20 to 100 mesh, the iron oxide fines with which the coal is mixed also being of this size. In one manner of mixing, the small portion of coal and the fines are proportioned by running out the materials from their respective bunkers on separate belts which merge and the two materials thus proportioned are intimately oxidation of the metallic-iron in the coke and improves the coking time.

In an advantageous embodiment of this invention, the proportions in the mixing of the iron oxide fines with the small fines portion of the coal can be such that the mixture constitutes 10% to 45% fine coal and 90% to 55% iron oxide fines, the amount of iron oxide fines being such that when this iron oxide-fine coal mixture is blended with the remaining portion of the total coal charge, the proportions are 20% to 60% iron oxide fines and to 40% coal.

For the purpose of further illustration, the table below indicates the improvement in hardness and stability of coke when prepared by the inventive process as distinguished from the prior practice of mixing the coal and ore at one time.

In the above table the overall mixture was composed of 60% Hernshaw seam high-volatile coking coal and 40% taconite concentrate blend.

The invention claimed is:

1. A process of manufacturing iron-coke comprising the steps of intimately mixing iron oxide fines with a minor fine portion of a total coal charge with which said fines are destined to be mixed, said iron oxide fines and said minor fine portion of the total coal charge having different fiow characteristics due to such differences as moisture content, blending said iron oxide-coal mixture with the remaining major portion of said total coal charge and coking said blended mixture.

2. The process of claim 1, wherein said iron oxide fines is a taconite concentrate.

3. The process of claim 1, wherein said iron oxide fines is a material derived from hematite ore.

4. The process of claim 1, wherein said iron oxide fines is a material derived from magnetite ore.

5. The process of claim 1, wherein said iron oxide fines is blast furnace fiue dust.

6. A process of manufacturing iron-coke comprising 3 minorlfinespcrtion .of aptotal coal charge 'with'whic'h said finesare to be mixed, said iron oxide fines and said minor fine portion of the total coal charge having different flow characteristics due- 'to such difierences as moisture content, saidmixture comprising (110% tu 45. fine coaL.and-90% :to ,5.5. iron :oxide fines,rblending saiddrqn oxide-coal mixture with the iremaining ,majqr, ipqrtionfpf said; total coal charge, saidblended mixture containing 20% 10.60%, iron o d -fin saand 80%.10 40% coal, and choking; said blended mixture. 7

References Cited in the file: of this patent UNIZITEDuSTAT-ES FPATENTS V 1,923,803 'Trent Aug. '22, 1933 2,429,416 Lesher Oct. 21, 1947 2,473,987 Brandon June 21, 1949 2,512,076 Singh June 20, 1950 FOREIGN PATENTS 598,316 Great Britain Feb. 16, 1948 267,960 Switzerland, Dec. 16, 1950 OTHER REFERENCES Ferrocoke by G. Cellan-J ones, Coke and Gas, vol. 1'5',"N0; 172, "September 1953,-pages 315-320.

U.S. Deptxof the Interior, lnforrnationCircular No. 7462,:.by;Erank.I -I5. ,Reed; entitled Some Observations on Coking Practice in Germany, June 1948, pages 9-12 incl.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,919,231 December 29, 1959 Ernest E. Donath It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 2, line 1, strike out "the steps of intimately mixing iron oxide fines with a? and insert the same after "comprising" in line "(2, same column.

Signed and sealed this 21st day of June 1960.

(SEAL) Attest:

KARL n. AXLINE ROBERT C. WATSON Attesting Oificer Commissioner of Patents 

1. A PROCESS OF MANUFACTURING IRON-COKE COMPRISING THE STEPS OF INTIMATELY MIXING IRON OXIDE FINES WITH A MINOR FINE PROPTION OF A TOTAL COAL CHARGE WITH WHICH SAID FINES ARE DESTINED TO BE MIXED, SAID IRON OXIDE FINES AND SAID MINOR FINE PORTION OF THE TOTAL COAL CHARGE HAVING DIFFERENT FLOW CHARACTERISTICS DUE TO SUCH DIFFERENCES AS MOISTURE CONTENT, BLENDING SAID IRON OXIDE-COAL MIXTURE WITH THE REMAINING MAJOR PORTION OF SAID TOTAL COAL CHARGE AND COKING SAID BLENDED MIXTURE. 